A listing agent describes the property as a legal non-conforming vacation rental. There's a Non-Conforming Use Certificate on file. The seller hands over two years of booking calendars showing steady 30-day turnover and a net income figure that makes the asking price pencil out. Everything about the paperwork says settled.
It isn't. The certificate proves the address once qualified for a status the city stopped granting decades ago. It says nothing about which rule currently governs how that property can be rented, because Oahu itself has not settled that question. Right now, two conflicting versions of the law exist on the books at the same time, and the gap between them is exactly where a buyer's income projections can quietly come apart.
Two Laws, One Address
In 2022, Honolulu Mayor Rick Blangiardi signed Bill 41, becoming Ordinance 22-7. The law raised the minimum stay for rentals outside resort-zoned districts from 30 days to 90, aiming to push short-term visitors out of residential neighborhoods and free up housing stock for long-term residents. City Councilman Brandon Elefante framed the goal plainly at the signing: the intent was to return residential neighborhoods to residential purposes.
The 90-day rule never took hold the way the council intended. A federal court granted a preliminary injunction in October 2022, halting enforcement of the new minimum. The Department of Planning and Permitting has since taken the position that it can only enforce the ordinance going forward, not retroactively, which means rentals that were already operating on the 30-day standard before the law passed get treated as legal nonconforming uses and can continue booking at 30 days. The city tried again with a second attempt at the 90-day rule in 2025, and that version is reportedly running into the same legal resistance the first one did. As of this writing, nobody with final authority has resolved which rule actually controls a given Kailua address.
That is not a footnote. It is the operating reality for every income property in this neighborhood that markets itself as a legal short-term rental.
Enforcement, meanwhile, has not slowed down waiting for the courts to sort this out. When Bill 41 was signed, DPP Deputy Director Dawn Takeuchi Apuna described the workload in Kailua and Lanikai directly:
We have an inspector that covers the area.
That single inspector's caseload was, at the time, almost entirely illegal short-term rental complaints. Kailua and Lanikai were the neighborhoods this bill was written to address.
What the Certificate Actually Certifies
Citywide, roughly 793 properties still hold legacy Non-Conforming Use Certificates. Honolulu stopped issuing new ones in September 1990. If a Kailua listing has an NUC today, it means the property was already operating as a rental before that cutoff and the city formally recognized it as an exception to zoning rather than a violation of it. Kailua and neighboring Lanikai are exactly the stretch of coastline where DPP concentrated its enforcement attention when Bill 41 was drafted, so a certificate here is carrying more scrutiny than the same paperwork might in a quieter zip code.
What the certificate does not do is freeze the rules that apply to that address going forward. It's a historical determination, not a permanent operating license. Here's the distinction that actually matters at the negotiating table:
| What the NUC Proves | What It Doesn't Prove |
|---|---|
| The property was operating as a rental before the 1990 cutoff | Which minimum-stay rule currently governs the property |
| The city formally classified the use as legal nonconforming | Whether the classification survives future litigation or a revised ordinance |
| The owner has a documented history with DPP | Whether the most recent annual renewal was actually filed on time |
| The property is one of a fixed, shrinking pool citywide | What income the property can generate under a 90-day minimum if that rule is ever upheld |
A buyer who treats the left column as the whole story is pricing the property on a document. A buyer who understands the right column is pricing it on a legal question still in motion.
The Inventory That Didn't Show Up
Here's the part of this story that runs against the obvious expectation. When a city cracks down on illegal rentals, the textbook prediction is that owners bail, listings flood the market, and prices soften as sellers compete to exit before enforcement catches up. Hawaii Business Magazine's reporting on the Bill 41 rollout found something different: the North Shore saw a sales uptick after the crackdown, but other neighborhoods known for illegal vacation rentals, Kailua among them, did not see a sharp increase in inventory.
That's worth sitting with. It means owners in Kailua largely didn't sell into the ambiguity. Some converted to 30-day-plus long-term rentals. Some simply held the property as a second home or a legal rental waiting for the courts to settle the 90-day question one way or the other. The effect for a buyer today is that the supply of documented, NUC-backed income properties in Kailua stayed thin rather than loosening up, and that scarcity sits directly on top of the legal uncertainty rather than resolving it. You're not choosing between a clear legal answer and a murky one. You're choosing among a small number of properties, all carrying the same open question.
The Honolulu Board of Realtors opposed Bill 41 on similar grounds, arguing through CEO Suzanne Young that the problems associated with nonpermitted and illegal vacation rentals in residential neighborhoods can be solved by enforcing existing law. That argument didn't stop the ordinance from passing, but it captures why enforcement, not the statute itself, ends up being the variable that actually decides what a given property can do.
The Paper Trail Worth Requesting
A seller marketing a Kailua property as a legal non-conforming rental should be able to produce three specific documents, and a buyer's offer should be contingent on seeing them before the inspection period closes:
- The complete file that originally documented the non-conforming determination for that specific address, not a general reference to the NUC program.
- The most recent completed renewal application and every attachment submitted with it.
- The renewal letter DPP issued in response, confirming the status was accepted for the current cycle.
Legacy NUC holders renew annually between September 1 and October 15. A lapsed or late renewal is worth asking about directly, since a gap in that filing history can undercut the legal status entirely regardless of what the original certificate says. If the seller lives off-island, confirm they've designated a licensed on-island agent as Hawaii law requires for owners of short-term and mid-term rentals. That requirement exists independent of the 30-day versus 90-day fight, and its absence is its own red flag.
None of this paperwork changes what happens if the 90-day rule is eventually upheld statewide. It does tell you whether the property's current 30-day operation is on solid administrative footing today, which is a different and more answerable question than what the law will say next year.
What This Means for Pricing
Income projections built on a seller's 30-day booking history are projections built on the current enforcement posture continuing, not on a settled right. Underwrite the property on that basis. Factor in the fixed cost of compliance either way, an 11 percent state Transient Accommodations Tax as of January 2026 plus the county TAT surcharge and General Excise Tax, since that tax stack applies whether the 30-day or 90-day rule ultimately wins. And weigh the $10,000-per-day fine exposure that comes with guessing wrong on which rule applies to a specific address, a number the city has used consistently across its vacation rental enforcement.
A Kailua income property with a clean paper trail and a current NUC renewal is still a defensible purchase. It's just a defensible purchase of a property operating inside an open legal question, not a closed one, and the price you pay should reflect that distinction rather than the acronym on the listing sheet.
FAQ
Does a Kailua property's NUC guarantee I can keep renting it short-term? No. It documents that the city recognized the use as legal before September 1990 and confirms the owner has kept up with annual renewals since. It does not resolve which minimum-stay rule, 30 days or 90, ultimately governs the property if current litigation changes course.
What happens if the 90-day rule is eventually upheld? DPP's current position enforces the ordinance prospectively, protecting properties that were already operating under the 30-day standard before the law passed. Whether that protection holds if a revised ordinance survives its next legal challenge is not yet settled, which is why the certificate should be read as evidence of current practice, not a permanent guarantee.
Where do I start verifying a property's status before writing an offer? Request the three-document file directly from the seller during due diligence and confirm the renewal history through DPP records rather than relying on a listing description alone.
For a closer look at what buying in this neighborhood involves beyond rental math, our guide to buying a second home in Kailua covers the broader picture, and our Kailua neighborhood page has current listings if you're ready to look at specific addresses.
If you're weighing an income property in Kailua and want a second set of eyes on the paper trail before you write an offer, Beth Chang has spent decades reading exactly this kind of documentation for Oahu buyers and sellers. Let's Connect.
